Alright, time to explain. While driving, pedal half way truck runs amazing. If I push the pedal to the floor, truck downshifts and at 3k it bogs out and doesn't want to accelerate.

I did a compression check on all cylinders, 150psi.
I replaced the cap and rotor, wires and plugs.

I had a cylinder 6 misfire, but it has gone since replacing the cap.

I was thinking the tps sensor or fuel injectors, any suggestions?

 

Does this happen at a certain gear change (assuming it's an auto, like the 2-3 or 3-OD shift?) Could be a governor pressure solenoid/pressure sensor issue in the tranny.........

 

How does the engine behave in neutral? Can you get it to rev past 3k? If not, you're looking at a clogged cat.

 

It is an automatic, in neutral it revs fine.. No hesitation at all.
It seems to happen from 2nd and up, even with overdrive off.. Even tried it in low, still the same.

I read somewhere that bank 1 o2 sensor can cause it? Or the pre-cat sensor?

As for the transmission that was replaced about 3000 miles ago and was fully rebuilt.

 

You might adjust the TV (Throttle Valve) cable on the throttle body. Those have been known to get buggered up when swapping transmissions.

 

It still can be a clogged/clogging cat, read the plenum stickie. And check fuel pressure with a gauge.

 

I'm jumping on the clogged cat/exhaust restriction band wagon. Does the check engine light flash off and on when it bogs? You can hook up a vacuum gauge to intake, then slowly bring rpm's up to 2500 plus. Normal vac reading should be around 17 or 18in with a steady needle. If the needle falls while increasing rpm,s, then she is clogged.

 

It's the cat.. I didn't test it, pulled out the upstream o2 sensor and drove it. It's loud, but runs like a beauty.

Now the real question! Any reccomendations on a cat? I dislike magnaflow so that's out of the list.

223000 on the same motor, still like new.

 

I use Merlflow or something like that.


Just out of curiosity, why do you dislike Magnaflow? They only make the best cats for these trucks....

 

I've had issues with magnaflow before on different vehicles and when it came to customer service, they lacked it quite a bit, it's not the product it's the people behind it.